It is known to use nitroxyl radicals/oxoammonium salts in the oxidation of primary alcohols to produce aldehydes and acids and secondary alcohols to ketones (Journal of Organic Chemistry, vol. 52 (12), pp. 2559-2562, and Journal of Organic Chemistry, vol. 55, 1990, pp. 462-466).
It is reported in the open literature that primary aliphatic alcohols can be converted to aldehydes in 30-40% yields in the presence of catalytic amounts of cuprous chloride, 2,2,6,6,-tetramethylpiperidine-1-oxyl, and atmospheric oxygen (Journal of American Chemical Society, 1984, 106, pp. 3374). It is also known that higher yields of aldehydes can be obtained if stoichiometric amounts of cupric or ferric salts are used instead of catalytic amounts of the cuprous salts (Pure and Applied Chemistry, vol. 62(2), 1990, pp. 217-222).
It has been found that aldehydes can be produced in good yields and with high selectivities from aryl methanols without producing large amounts of other products such as acids and esters. This can be accomplished by using catalytic amounts of a stable free radical nitroxide, a NO.sub.x -generating compound and optionally, an oxidant and/or a solvent.